Endocrinology.pdf

Endocrinology - Neurotransmitter is released by axon terminals of neurons into synaptic junctions - Endocrine hormones: are secretion of glands into circulating blood - Neuroendocrine hormones are secretion of neurons into circulating blood - Paracrines secretion of cells into extr...

Endocrinology - Neurotransmitter is released by axon terminals of neurons into synaptic junctions - Endocrine hormones: are secretion of glands into circulating blood - Neuroendocrine hormones are secretion of neurons into circulating blood - Paracrines secretion of cells into extracellular fluid affect the neighboring cells of different types. - Autocines secretion of cells into extracellular fluid effect the function of the cells that produces them. - Cytokines: secretion of cells into extracellular fluid can work as paracrine autocrine and endocrine. Work as autocrine, paracrine and endocrine. Three general classes of hormones exist: - Proteins and polypeptides: hormones secreted by posterior and anterior pituitary gland, the pancreas (insulin and glucagon) parathyroid gland (parathyroid hormone, and many others. - Steroids: secreted by adrenal cortex (cortisol and aldosterone) ovaries and placenta (estrogen and progesterone) - Derivatives of the amino acid tyrosine, secreted by thyroid (thyroxine and triiodothyronine). Polypeptide and Protein Hormones Are Stored in Secretory Vesicles Until Needed - Polypeptides with >100 more amino acids are proteins - Polypeptides with